A mashup of various code snippets for case-specific (Barcode and QR code scanning) use.

code_scanner.py

# Barcode and QR Code scanner
# Created by F.O.Emre Erdem
# A mashup of various code snippets for case-specific use.
# Sources:
# https://www.learnopencv.com/barcode-and-qr-code-scanner-using-zbar-and-opencv/
# https://www.pyimagesearch.com/2018/05/21/an-opencv-barcode-and-qr-code-scanner-with-zbar/

from __future__ import print_function
import pyzbar.pyzbar as pyzbar
import numpy as np
import cv2
import argparse 

def decode(im) : 
  # Find barcodes and QR codes
  decodedObjects = pyzbar.decode(im)
 
  # Print results
  for obj in decodedObjects:
    print('Type : ', obj.type)
    print('Data : ', obj.data,'\n')
     
  return decodedObjects
 
 
# Display barcode and QR code location  
def display(im, decodedObjects):
 
  # Loop over all decoded objects
  for decodedObject in decodedObjects: 
    points = decodedObject.polygon
 
    # If the points do not form a quad, find convex hull
    if len(points) > 4 : 
      hull = cv2.convexHull(np.array([point for point in points], dtype=np.float32))
      hull = list(map(tuple, np.squeeze(hull)))
    else : 
      hull = points;
     
    # Number of points in the convex hull
    n = len(hull)
    qrData = decodedObject.data.decode("utf-8")
    qrType = decodedObject.type
    # Extremely sketchy way to take the top-leftmost point. ¯\_(ツ)_/¯
    x=hull[0][0]
    y=hull[0][1]
    # draw the QR data and QR type on the image
    text = "{} ({})".format(qrData, qrType)
    cv2.putText(im, text, (x-20, y - 10), cv2.FONT_HERSHEY_SIMPLEX, 0.35, (0, 0, 255), 1) 
    # Draw the convext hull
    for j in range(0,n):
      cv2.line(im, hull[j], hull[ (j+1) % n], (255,0,0), 3)
      print(hull[j][1])
 
  # Display results 
  cv2.imshow("Results", im);
  cv2.waitKey(0);
 
   
# Main 
if __name__ == '__main__':
 
  # Read image
  ap = argparse.ArgumentParser()
  ap.add_argument("-i", "--image", required=True,
  help="path to input image")
  args = vars(ap.parse_args())
  # load the input image
  im = cv2.imread(args["image"])
  decodedObjects = decode(im)
  display(im, decodedObjects)